Half to john a



g UNITED STATES PATENT OFF-ICE.

ELWOOD T. THORNER, OF CAMBRIDGE CITY, INDIANA, ASSIGNOR OF ONE- HALF TO JOHN A. sP NoE, or sAME PLACE.

METAL-SHEARS.

SPECIFICATION forming part of Letters Patent No. 484,203, dated October 11, 1892.

Application filed February 15, 1892 Serial No. 421,586. (No model.)

to the letters of reference marked thereon,

which form a part of this specification.

My invention relates to improvements in metal-shears or machines for cutting sheet metal; and it consists in certain novel features which will be hereinafter described and claimed.

The primary object of my invention is to provide a simple and efficient machine by which the metal plates may be out without the expenditure of a great deal of labor and in which the plate will be securely held while being cut. This object I accomplish by the use of the mechanism illustrated in the accompanying drawings, in which- Figure 1 is a perspective view of a machine constructed in accordance with my invention, and Fig. 2 is a vertical transverse section of the same.

Referring more particularly to the drawings, A A designate a pair of standards having the forward extensions B, to and between which I secure a bed-plate O, the said standards and bed-plate constituting the supporting-frame of the machine. The standards are further provided with the vertical guide portions D, to which I secure the caps E,between which and the said guide portions the reciprocating jaw F plays. The reciprocating jaw F and the bedplate 0 are provided with knives, which act on each other with a shearing movement, so as to out the metal. The reciprocating jaw is further provided in its rear side near its ends with'the racks G, which are engaged by' the segmental gears H, pivoted to the inner sides of the standards. The rear ends of the said segmental gears are connected by the links I with the rear end of a treadle J, which is pivoted near its front edge to the standards. The foot-rest K consists of a plate L and the arms or levers M, extending rearward from the said plate and having their rear ends hinged to the rear edge of the treadle. A bolt or headed pin N rises from the treadle near the'front edge of the same and passes through a'longitudinal slot in the arms M. Springs 0- are arranged between the treadle and the said arms, so as to hold the same normally upraised. A spring P is arranged between the foot-rest and the bedplate and tends to lift said foot-rest, so that it will act upon the treadle andits connections to hold the reciprocating jaw in its raised position.

At the upper end of the standards I provide the bearings Q, in which a rock-shaft R is journaled. This rock-shaft is provided at its end with the vibratory arms S, having the connecting-rods T U, pivoted to and depending from their front and rear ends, respectively. To the lower ends of the front connecting-rods T, I secure the presser-bar V, which is arranged in advance of the reciprocating jaw and is guided in its movements by the keepers W, which are secured to and project inward from the caps E. The rear connecting-rods U have their lower ends pivoted to the rear end of angle-levers X, which are fulcrumed on the inner sides of the standards and are provided with the bentslots Y, which are engaged by studs Z on the sides of the arms M.

In practice the metal which is to be acted upon is placed on the bed-plate with the length which is to be cut off extending under the reciprocating jaw. The operator then depresses the foot-rest, and the presser-bar and the jaw are in consequence successively brought down onto the metal plate, so as to act on the same. When the foot-rest is depressed, the studs Z first ride along the shorter arm of the angle-slot Y, so as to oscillate the angle-levers X, thereby raising the rear ends of said levers, and consequently oscillating the crank-arms S, so as to depress the presser-bar V and cause the same to bear on the metal plate, so as to hold the same firmly against the bed-plate while being cut and at the same time remove any corrugations or other irregularities in the metallic plate. By the time the studs Z have reached the bend in the slots Y the springs 0 will be compressed to such an extent that the continued downward movement of the foot-rest will oscillate the treadle and lift the rear end thereof, thereby vibrating the segmental gears, which act on the jaw so as to lower the same, and thereby bring the knife into action to cut the metal. Upon relieving the pressure on the foot-rest the spring P instantly lifts the same and causes a reverse movement of the several parts, thereby restoring them to their initial positions.

My improved machine is very simple in its construction and is composed of few parts, so that it can be built at a comparatively-slight cost, and as it is free from complicated combinations it will be found very durable. The arrangement of the several parts is such as to produce a powerful action with the expenditure of a minimum amount of force, and

.the advantages of the machine are thought to be obvious.

It will be noted that in my machine the presser-bar is first brought down onto the sheet of metal and clamps the same against the bed-plate, so that it will not buckle while being cut.

Having thus described my invention, what Iclaim,and desire to secure by Letters Patent, is

1. In a machine for cutting metal, the combination of a presser-bar, vibratory arms connected with said presser-bar, an angle-lever connected with said vibratory arms by connecting-rods and provided with an angle-slot, and an operating-arm provided with a stud engaging the said slot.

2. In a machine for cutting metal, the com normally raised, a presser-bar, a knife-carry ing jaw, connections between the said jaw and the treadle, and connections between the presser-bar and the an gle-levers.

In testimony whereof Iaffix my signature in presence of two witnesses.

ELWOOD 'l. I-IORNER.

\Vitnesses:

H. B. BOYD, O. H. TABKE. 

